Field of the Invention
The present invention relates to wireless communication, and more particularly, to a method of transmitting a positive-acknowledgement (ACK)/negative-acknowledgement (NACK) for hybrid automatic repeat request (HARQ) in a wireless communication system, and an apparatus using the method.
Related Art
3rd generation partnership project (3GPP) long term evolution-advanced (LTE-A) is a technique satisfying a bandwidth of up to 100 MHz and a data rate of up to 1 Gbps. Carrier aggregation (CA) is one of techniques for increasing a maximum bandwidth by using a plurality of component carriers. One component carrier operates for one serving cell, and as a result, a terminal receives a service provided from a plurality of serving cells.
With the increase in the number of supported serving cells, an amount of feedback information reported by the terminal also increases. The feedback information includes channel state information (CSI), hybrid automatic repeat request (HARQ) ACK/NACK, or the like.
A physical uplink control channel (PUCCH) is defined for transmission of the feedback information. 3GPP LTE-A provides various PUCCH formats such as a PUCCH format 1/1a/1b, a PUCCH format 2/2a/2b, a PUCCH format 3, a PUCCH format 4, a PUCCH format 5, or the like according to a payload size.
With the increase in the number of serving cells supported in a CA environment, a method of transmitting uplink control information is proposed.